Timer



April 16, 1946. 1E. G. HENRY` TIMER Filed Feb. 18, 1944 3 Sheets-Sheet i.Mrt/zeg April '1% 1946. a G. HENY TIMER Filed Feb. 18, 1944 ssheets-shee'c'zA Patented Apr. 16, 1946 TIMER i Y Earle G. Henry,Wilmette, Ill., vassignor to Buckley Music System, Inc., a corporationof Illinois Application February 18, 1944, Serial No. 522,919

`(Cl. 'i4-54) 3 Claims.

There is a common form of timing `device wherein one or more elements`that actuate or carry switches or other things are rocked back Vandforth by a revolving cam shaft; separate cams being employed for eachelement, when their timings are required to be different. Such deviceshave been unsatisfactory in some respects on account of limitationsimposed by the cams. While a cam roller can drop abruptly from a high`section of a cam to a low section, the reverse is not true; a gradualslope being required between two such cam sections to enable the rollerto climb uphill. Therefore the rocking movement of the driven element isnecessarily slow in one direction. If the work that the rocking elementt is to do is to open and close a switch, for example, serious arcingmay occur due to slowness in opening the switch, even if it be a mercuryswitch. Also, because of the considerable length of time required for acam roller to shift fully from the low section of the cam to the highsection, the interval of time between leaving the high section and againreturning to it must always be a substantial one, particularly in thecase f a very slowly rotating cam shaft. Consequently, if a switch, forexample, is in a Aclosed position while the cam roller is on the lowsection of a cam, it

cannot be opened immediately after beingclosed,

but only after the rollerhas had time to ascend a gradual slope; therebyplacing an undesirable limitation on the possible range of ratiosbetween the time that the switch maybe open and vthe time that it mayremain' closed in each cycle of operations.

The present invention has for its object to produce a simple and noveltimer construction in which the driven or controlled member is shiftedspeedily from each of its two positions to the other and may return fromone of such positions to the other after being there for practically theshortest measurable time, if desired.

The various features of novelty whereby my invention is characterizedwill hereinafter vbe pointed out in the claims; but, for a fullunderstanding of my invention and of its objects and advantages,reference may be had to the following detailed description taken inconnection with the accompanying drawings, wherein:

Figure l is a front view of a fragment of a panel having thereon one ofmy timers; Fig. 2 is a section on line 2 2 of Fig, 1; Figs. 3, 4 and 5are sections on line 3-3 of Fig. 1, showing the parts in three differentpositions; Fig. 6 is a section on line 5 of Fig. 1; Figs.'7 and 8 are aside view and an edge view of one of the cams visible in Fig. 6; andFigs. 9 and 10 are a side view andan edge view of `the second cam seenin Fig. 6. l t

In the drawings I have illustrated my invention in an apparatus whereinthe controlled member, that is the member whose movements are to betimed, carries a switch or switches; and, for the sake of brevity, thedetailed description will be confined to this particular embodiment, as

`the alterations needed to adapt the device to other uses `or to othermanner of uses can easily be made.

Referring tothe drawings, l and 2 are like switch carriers Vmounted soas to be capable of moving back and forth through a limited distancebetween two working positions. In the arrangev ment shown, these membersare sturdy lmetal plates, more or less rectangular in shape, supportedon a stationary, horizontal shaft 3 for rocking movements independentlyof each other in parallel, vertical planes. These elements, as well asthe shaft 4, below, a little in front of and parallel to the shaft 3havelong been used in a timer to which my invention can readily be applied;the number of switch carriers depending on the number of switches to beoperated. The shaft 4, which is a cam shaft, is shown as being v4drivenfrom a drive or timing shaft 5 by a pinion E on the latter meshing witha gear l on the cam shaft; the shaft 5 being conveniently driven, as .Yheretofore, by a constant speed motor, not shown. .The shafts 3 and 4are shown as being supported in suitable bracketsA 8, 8 on a base member9 that `isfin turn mounted on a suitable panel, I0.

`Mounted on the shaft 3,`beside but spaced a short distance apart fromeach of the switch carriers or controlled members is a dog orcontrolling member Ilcapable of rocking independently of each other andof theY carriers. 0n each carrier, forwardly of the shaft 3, is apin l2that projects across the plane of the corresponding dog, so that whenthe latter assumes a predetermined angular position relative to itsswitch cari'rier its yforwardly extending arm contacts the pin, Atension spring I4 extends between and is .connected at its ends to a pinl5 on the other arm of the ldog and a pin i6 on the switchcarrier.

VThe parts are soa'rrangedthat the spring I4 of each` unit yieldinglyholds its dog in contact with the pin or stop shoulder l2 on theadjacent switch carrier, whenfree to do so. Associated with each ofthetwo units is asecond spring l1 which extends between and is connected atits ends to the pin I5 and a'pinil projecting from the front.'side'ofthebaseS. f

On the cam shaft are two sets of cams, one for each unit, each setincluding a cam cooperating directly with the corresponding switchcarrier and a second cam that acts on the dog or conhundred and twentydegrees and a maximun. angular length of about two hundred and forty 5Fig. l and causes it to drive the carrier to the rearward position, asseen in Fig. 5. As the rotation of the cam shaft continues, the gradualupward slope 25 on the double cam reaches the cam roller 3i! and causesit to ride up until it rests on the high section of the cam. This locksthe switch carrier against forward movement until the abrupt slope 24again reaches the cam roller 30 and allows it to drop. After the memberhas v'been made secure with the switch Ain its open position, theincline 2S on the cam 26 engages the cam roller on the dog ll, causingthe dog to "rock in the counter clockwise direction from the -"positionoccupied in Fig. 5 to that in Fig. 3 where the two disks, relatively toeach thr'theremainder of the periphery'bingthe lowfsection of the cam.One end of the low section uterminates at a radial shoulder 24 whichiets the adjacent en'd 'of the hi'gh Vsection v"of "the "cam, while `theother end of the low vsection'merges into a gradual upward slope 25which, in'turn,

-merg'es with the high'section. The second cam ofeach set may :be`a'singleY mutilated disk 26 havin'g a .peripheral arc-shaped highIsection 21 of about twohundre'd and tenfdegreesfjoined lat one end'tolalow section by a radial slope 28, whereas .a .gradual slope k29 `joinsthe other'en'ds `of the two sections together. The l'aforesaid Vangular.lengths sarefgiven by Ivvay of example rand-"may,` of

course, be altered to suit conditions to b'e met. This is also truelwithrespect tothe angles of the slopesfthat connect thefhigh and lowsections of the cams together.

Eachofthe :switch 'carriers has `thereon a cam roller 3e 'cooperatingwith thetwo-piece or double cam; andeach rocking 'dog is provided with acam roller 3| vthat is 'at all times inengagement with the correspondingcam 26.

- The camshaft is driven in the clockwise direction as viewed inFig.2"a'nd Tin-the 'counter clockwise direction as viewedin Figs.A 3, 4,"5and v6.

The member is shown as having va "single mercury switch --Amounte'dther'eon, while there are two-such switch'esB'and C, onfcarrier-2. The switches A and-3B close when their carriers `are -f c'ockedfforward and-open"'whe'n Vthe carriers are rocked into theirrearward-positions.

. The operation will nowlbe explained. VIt will be -seenifrom Figs.2 and3,`which indicate like'p'osl-r tions of"all'parts, lookingat the unit atthe-left hand end iin Fig. 2, that the carrierl is in nits rearward"position, the switches AA 'and-B being `open -and the switch C beingclosed. `The cam- Vroller 30 is resting on fthe high lse'c'tion of thedouble cam and the camlroller 3|i's on the high section of cam 26. Itwill be seen that 'as fthe cam shaft turns in the fdirection of4thearrow's in these gures, no change in'theipositionsfof the- Fig. 4.Because it yis .assumedathat `switch A -is to remain Vclosed only a veryshort time,'the cam .roller 3| is very close to -the 'abrupt slope onits cam but still is supported on the high part `of* the cam; Duringlallthis time-the spring i1 has been -under amaximumtension so that,when'the `cam -roller 3| reaches the abruptfslope 28, this spring thedog is shown rocked down away from the pin orslriouldei' il 2 pntheswitch carrier. This move- 'me'tof 'the do`g"stretches the spring I4which is '-thenffree to snap the carrier forward, without interferenceon the part of the dog when the "camroller 30 is again in position todrop off the high-section-of Vthe double fcam, `as inFig. 4.

Thecams fare provided with hubs 4.t3 'and3, reffspe'ctivelm which'may bexed to the vcam shaft byset screws '35. Upon -loosening the set screwsthe vvcams may be shifted angularly of the cam shaft, to 'adjust them,and then be `secured by again tightening the screws. The period forwhich the switch remains closed may thus be var- Vie'd both by changingthe relative angular-.positions of the two cams and by making theadjust- Vments required to change the length of the high section of thedouble cam. Thus, the unit having Iassociated therewith the twoswitches, B and C, has the high section `of its double ca'rn sh0rtenedthrough the adjustment of the two disks anlgularlyof `each other; while,'as shown in'Fig. 6, .the lcam-26 of this unit is not quite in the sameangular position relative to the double 'cam as is the case in the firstunit. previously stated, the construction of the corresponding cams inthe two units is the same, so that Figs. 7 to 10 of the drawings may besaid to illustrate either set, although showing the adjustments, as theyappear -in Fig. 6, of the cams in the second unit which 'contains theswitch carrier.

Whether a switch be opened or closed when `a carrier 'isrocked in onedirection or the other depends, of course, on which end thereof is onthe -front side. Thus, in the second unit, 'the switches -B and C rareso disposed ythat whenever one is .open-the other is closed.

While any suitable means may be` employed to --keep the controlledmembers and the'controlling members properly spaced on their' supportingshaft,V V'sleeves 35V of insulating material and sheaves 31, also ofinsulating material and adapted to serve as guides f-orleads (notsho'wn)to the switches may be used.

,fIn -the particular construction illustrated provision is made for onlythree differentrelative angular positions 'of the two disk-dike'elements of the two-piece cam. However, because of the proportionswhich the two cams have 'and of the ca- .pacity for adjustment of thecams bodily, angularly with respect to each other, any 'desired timingcycle may be obtained. At the `same time, when the fastening screws `aretightened, the two members of the double cam are locked together--solidly Vin such a Way that accidental relative angular displacementduring use is impossible.

' .The most important feature of my invention, Yit`'wi1l befperceived,is that the controlled mem- A'ber is permitted to move rapidly from oneexat-reme position'to :the other inthe same manner rocks the dog in theclockwise :rectionas'viewed 7:5 :asf-Would "bathe-case if'itwereIpossibleftoaconstruct a single rotatable cam that could shift a rollerfrom a low section to a high section as rapidly as a roller can drop inthe opposite direction. The rapidity of the shift is determined solelyby the needs of the service to be rendered. Thus, in the exampleillustrated, the mercury switches should be shifted rapidly but, also,gently, to avoid the creation of oscillatory movements of the mercury atthe end of a shifting movement of the same. Consequently, the movementof the cam rollers down the steep slopes of the double cams should bechecked a little; whereas, on thel other hand, since the single cams donot act directly on the switch carriers, the dropping of the rollers onthe rocking doris or controlling members may be instantaneous ifdesired.

While I have illustrated and described with particularity only a singlepreferred form of my invention, I do not desire to be limited to theexact structural details so illustrated and described; but intend tocover all forms and arrangements coming within the definitions of myinvention constituting the appended claims.

I claim:

1. A controlled member whose movements and periods of rest are to betimed, a controlling member, `said members being mounted side by sidefor independent movements back and forth, a shoulder on the controlledmember in position to be engaged by the controlling member when thelatter is moved into a predetermined position relative to the othermember, a spring connecting said members together and tending constantlyyieldingly to hold the shoulder and the controlling member in engagementwitheach other, a second spring tending constantly tomove thecontrolling member in the directionto drive the controlled member to apredetermined rearward position, two cams rotatable in unison with eachother, one cam cooperating with the controlled member and having such acontour that it lifts and then locks that member in said predeterminedrearward position during a predetermined part of each revolution andthen abruptly leaves it free to return to a predetermined forwardposition, and the other cam acting on the controlling member and havingsuch a contour that during a predetermined part of each revolution itmoves the controlling member into and holds it in a retracted positionand then abruptly leaves it free to move in the direction to drive thecontrolled member into the vicinity of the said predetermined rearwardposition of the latter.

2. A controlled member whose movements and periods of rest are to betimed, a controlling member, said; members being mounted side by sidefor independent movements back and forth, a shoulder on the controlledmember in position to be engaged by the controlling member when thelatter is moved into apredetermined position relative to the carriermember, a spring connecting said members together and tending constantlyyieldingly to hold the shoulder and the controlling member in engagementwith each other, a second spring tending constantly to move thecontrolling member infthe direction to drive the controlled member to apredetermined rearward position, two cams rotatable in unison with eachother, each cam having a high section and a low section, the trailingend of the high section of each cam dropping abruptly to the low sectionand the trailing end of each low section being connected to thecorresponding high section by a gradual slope, and a cam roller on eachof said members in operative relation to oneof the cams.

3. A construction such as set forth in claim 2, wherein the cam thatcooperates with the controlled member is adjustable with respect to therelative lengths of the high and low sections, whereas the other cam hasa high section about as long as the maximum length of the high sectionof the first cam and a low section about equal n to the minimumlength-of the high section of the rst cam.

- EARLE G. HENRY.

